A headless, cylindrically-shaped item having a straight, smooth, solid body, with or without a drilled hole(s). It has an outside diameter equal to or less than its length. Its length must not exceed twelve inches (304 MM); for items whose length exceeds twelve inches (304 MM); see ROD, STRAIGHT, HEADLESS. It is used for aligning or transfer of torque and/or thrust, by fitting into corresponding holes of another item. See also PIN, STRAIGHT, THREADED.